The purpose of this study is to evaluate the efficacy of recombinant human erythropoietin (Rhu-epo) given to newborns 401-1,250 grams birth weight beginning in the first four days of life and continuing through discharge or 35 weeks post-menstrual age on the number of blood donor exposures, the number of blood transfusions, and the proportion of non- transfused preterm infants. Enrollment began in the fall of 1997 and will last approximately another year.